How does you iMac run when you're maxing out the processor. Does it heat up alot? Noisy fans? Any noticeable stalling especially in regards to hyper-threading?

The iMac is a gift so I might be able to get the 8/16GB and 2TB ATA drive covered. If that was not the case, yes, I would look someplace else for those upgrades rather than being locked into Apple prices.

I wish the internal drives (and memory?) were DIY. I know it can be done but it is not as simple as opening up a MacPro. The warranty would be voided if you DIY. Then there is the hassle of dragging the iMac to an Apple store or ASP depending on the upgrade. I just want to customize the iMac so I do not have any need to open the case up until the Apple Care warranty is over.

No problem!!!

Well, I don't know that you'll be able to actually max it out It's pretty powerful, I guess maybe if you play some extreme games or something… But, when I'm really working it hard, it never gets truly "hot". It will get very warm though. A lot of people worry about that, but you have to remember… The ventilation slot where the hot air comes out, is at the top of the machine. It does get warm there. The case is aluminum to help dissipate heat, and it gets warm too. It's designed as a giant heat sink, essentially. This makes the case warmer than most other machines, but it also allows for the fans to cool much more while running at far lower speeds. I've only heard the fans get truly loud one time, and that was when it had been rendering a video I was making for about a half hour-hour or so, and I was doing some other things as well. But even then it wasn't "hot".

Never had it stall once, at all. Even when doing multiple "large" tasks at once.

The memory is VERY easy to change on the iMac, and MBP. The instructions are in the manual, and it's actually easier than the last PC I had!! As far as I know the warranty is not voided if you do the RAM. The HDD yes. The only way you'll void the warranty doing the RAM, is if you damage something. That being said, other modifications in the traditional sense of computers, are more or less impossible. Nature of the beast my friend Like a laptop, all in one machines like the iMac are designed to very close tolerances, and there's not a lot of room in there to change things around.

I can't speak for running Windows in Bootcamp, I have no use whatsoever for Windows personally. But under OS X at least, doing everything one can think of, this machine with this processor absolutely screams. You really won't be disappointed, as far as I can tell you